Pivot lathe for watchmakers



Oct. 9, 1923; 1,470,544

D. K. ROBINSON PIVOT LATHE FOR WATCHMAKERS Filed Aug. 5, 1922 WTTTFI THWITNESSES fwwzw 42%? m 'IIIIIILIVIAW Patented Oct. 9 1923.

1 UNITED STATES "PATENT OFFICE.

DEAN Kayne aoisrnson, or BALTIMORE, MARYLAND.

PIVOT LA'rI-in For. wA'ronMAKnns.

Application filcdAugust 5, 1922. Serial No. 579,859.

To all whomitmay concern. j

Be it known that I, DEAN K. ROBINSON, a citizen of the United States,and a resident of Baltimore, in the county of Baltimore City and Stateof Maryland,have invented a new and Improved Pivot LatheforVVatchmakers, of which 'the following is a full,

clear, and. exact description.

This invention relates to pivot straightening devices and lathes forhorological balance wheels and train gears, and has reference moreparticularly to a lathe having one pivot supporting member movable alongthe axial plane of the pivot, and another movplane transverse to theaxisof the 1 member movable in a plane transverse to the axial planewof thepivot.

Further objects'will appear as the specification proceeds, of which thedrawings form one part, it being understood that the same illustrateonly one example of the invention, since itcould be easilychangedwithout departing from the spirit of the invention.

Inthe drawings: a c

Figure 1 isa side viewof the device showin certain of its parts insection to more 0 early illustrate the same; I t

Figure 2 is a top vie-w of the device;

Figure 3 is an end view of the device showing the balance wheelsupporting end;

Figure 4 is a detail view of Figure 3 with one supporting memberremoved; and

Figures 5 and 6 are detail views of an element to be hereinafterreferred to.

In carrying out my invention in accordance with the illustrated example,a base or bench plate 1 is provided with openings 2 adapted to receivescrews 3 by means of which it is secured to the work bench A. Said benchplate 1 also presents a pair of bores 4: adapted to receive pins 5forming a part of frame 6, which presents a substantially U-shapedstructure with one leg formed with a head 7 throug which exten s a bore8 adapted to slidably receive a pintle 9. The other leg'of said framepresents a pair of threaded openings 10' andlll adapted to receive apivot screw 13 and a clamping To the upper end of bar 12 is secured ablade 15 provided withaseries of openings or pivot holes 16, each ofwhich can be brought in line with the. axis of pintle 9 screw 14,respectively, by means of which bar 12 is rookably held against saidframe.

by swinging the bar on pivot 13 and clamping the same against movementafter the desired adjustment has been made. i i

The blade 15 ispreferably thin to :permit a train gear or balance wheelpivot to proholes in order to have itsprojecting point inspected,straightened or refinished. The pintle 9 has oneend threaded toreceive anut 17, preferably beveled adjacent its inner .ject outwardly wheninserted in one of said end and slotted at its opposite end, as at 18(Figure l), for providing 'tool engaging members to effect its screwingor junscrewing on the pintle. At the other end of said pintle isarranged a head 18 for moving the pintle in said bore 8 and at a pointinter- 1 mediate its ends has a projection, or collar 19, alsopreferably beveled for a purpose hereinafter set forth.. N v I Saidpintle .revolubly carries between its threaded endand the collar 19 asleeve20 having a grooved pulley 21 at one end and a collar 22 at theother. The bore of said sleeve flares outwardly adjacent its ends tosnugly engage the beveled collar 19 and the nut 17 The threaded end ofthe pintle has I in its center a pivot bearing notch or center point,whereby a train gear can be "interposed and rotatably held between thepintle and the blade 15.

The collar 22 is formed with a slot 23 which preferably has a curved endwall 33 and which splits a portion of said collar into two parts 24 and25, through which passes an opening 26 adapted to receive the shank of afork 27. In said slot 23 is arranged a flexible bar 34 which normallypresses against the shank 27 when the same is inserted in the openings26, and thereby the same is held in place against displacement. The fork27 is adapted to engage the spokes of a balance wheel or the like, andthrough .it the balance wheel is made to revolve with -the sleeve 20;

The head 7 has a threaded opening 28 intersecting the bore 8 and saidopening is adapted to receive a screw 29 which is screwed tight againstthe pintle 9 to hold the latter in place once it has been moved towardthe blade 15 to engage a train gear in terposed between the blade andthe pintle.

hen the pivot point ofa balance wheel is desired to be inspected,straightened or repaired, the same is inserted in one of the openings16, which by means of adjusting screw 14 is brought directly in linewith the known in the horological art and therebythe rotation of'saidsleeve is imparted through the: fork 27 to the train gearinterposedbetween the pintle 9 and the blade 15.

' I would state in conclusion'that while the illustrated exampleconstitutes a practical embodiment of my invention, I do not limitmyself strictlv to the exact details herein illustrated, since,manifestly, the same can be considerably varied, with-out departingfrom. the spirit of the invention as defined in the appended claims;

I: claim:

1. Tan. adeviceof the character described, a frame, p'intlemounted onthe frame for longitudinal adjustment and. having one end thereofprovided with work engaging means, a clamping screw for securing thepintle in adjusted position,..a' blade adj ustably mounted on. the,frame: and having. a plurality of holes; selectively cooperable with thework engaging-means of the pintle for supporting the work for rotary;movement while leaving the same: accessible, and means mounted on thepint-1e for imparting rotary movement torthe Work.

2.11m a device of the character described, a frame, a; pizntle mountedon the frame for longitudinal adjustment and having one end thereofprovided with work engaging means, i

a clamping screw for securing the pintle in adjusted position, a bladeadj ustably mounted on the frame and having aplurality of holesselectively cooperable with the work engaging means. of the pintle forsupporting the Work for rotary movement while leaving the sameaccessible,said pintle having a portion externally threaded and beingprovided with a beveled collar, a sleeve fitted on the pintleand havingone end shaped to rotatably fit on said beveled collar, a nut engagedwith the threaded portion of the pintle and having a beveled end, thesleeve having a beveled portion adapted to rotatably fit the inner endof the nut, a pulley formed on the sleeve and means for transmitting therotary movement of the sleeve to the work.

3. In a device of the character described, a frame, a pintle mounted onthe frame for longitudinal adjustment and having one end thereofprovided with work engaging, means, a clamping screw for securing thepintle in adjusted position, a, blade adjustably mounted onrthe frameand having a plurality of holes selectively cooperab'le with the workengaging means of the pintle for supporting the work for rotary movementwhile leaving the same accessible, said pintle having a portionexternally threaded and being provided with a beveled collar, a sleevefitted on the Pintle and having one end shaped to rota-tably fit on saidbeveled collar, a nut en gaged with the threadedpo-rtion of the pintleand having a beveled end, the sleeve having a beveled: portion adaptedto rotatably fit the inner end of the: nut, a pulley formed on thesleeve and means: for transmitting the rotary movement of the sleeve tothe work, said means including a collar carried by the sleeve having alongitudinal opening, and a transverse: slot" intersecting the opening,a for-kcarried in the longitudinal opening of the collar and adapted tobe engaged with the work, and a resilient bar arranged 1n the slot andadapted to press against the fork'to hold: the same in position.

DEAN KEYES ROBINSON.

